Publisher/Editor: >■ D. Cheek, Sr. aka "Dr. Rigormortis" _ V2H4: April, 1992
THE WORLD SCANNER REPORT
k Journal of VHF-UHF Scanner Technology k Engineering
Published at: COHHtronics Engineering: PO BOX 262478; San Diego, CA 92)96 Copyright (c) 1991-2
_ ISSN 1061-9240
(All Rights Reserved) _ $4.00
SORRY FOR THE ERROR LAST MONTH
Every page of last month's issue has an error in the Vol/
Number where it's incorrectly given as "V2N2". The
correct entry should be "V2N3". You might want to make
pen & ink changes to your copies to eliminate confusion
in the future when we refer to certain backissues. Sorry
for any inconvenience this may have caused.
TIME TO RENEW FOR SOME
If your mailing label says, "Expire Date: May 92", then
you have one more issue coming before your subscription
expires. If it is convenient, you may want to renew
right away to get it off your mind. Otherwise, we'll
remind you again next month.
OUR BBS GOING STRONG - LOTS OF FILES & MESSAGES
I am gratified that our new BBS, the Hertzian Intercept,
is doing so well despite the very inconvenient hours. We
apologize for the limited hours and you can rest assured
that we're doing all we can do to get a 3rd phone line in
here so it can be dedicated on a 24-hr basis. For the
time being, the best time we can offer for you to get
through is midnight to 6:00 am, PST, BUT just for WSR
readers, here's a little clue: The BBS is automatically
switched ON at 8:00 pm and OFF at 8:00 am, PST. You CAN
try to get through anytime between those hours. The thing
is, is that I'm usually doing computer work until nearly
midnight and again starting at about 6:00 am, so take
that into account if you get a continuous BUSY signal.
The BBS's published hours for the World-At-Large remain
midnight to 6:00am, but you dear Readers are invited to
try anytime between 8pm-8am, PST. If the computer is
busy, you'll get a busy signal; if it's open, the BBS
will answer, so maybe it is worth a try. Our BBS number
remains (619) 578-9247 for the present. We now have an
official FidoNet Address for electronic mail: 1:202/731
if you have the capability for Direct NetMail.
INTRODUCING THE WORLDWIDE FIDONET BBS NETWORK
One of Hobby Radio's Finest Toolsi _
Speaking of computer bulletin board services (BBS), I
just have to share with you some inside scoop on a vast
resource of ideas, information, knowledge and opinions on
hundreds of subjects, including SCANNING and SHORTWAVE
LISTENING! I hope this article motivates you to put a
computer on the list of tools that support your radio
hobby. It might well become more useful and rewarding
than your radio equipment! Imagine an engineer without a
calculator; a bus driver without a bus; and a carpenter
without a hammer! You just might forever after wonder
how you managed to play radio without a computer. We all
know how offices managed to do very well without word
processors and copiers only a few years ago. And we radio
buffs managed quite nicely, too. The computer has opened
doors to all areas of human pursuit thanks to automation
and to a enormous volume of instantly available data and
information. The five-person office of today does the
work of what it took fifty to do 25-yrs ago. Today's
radio hobbyist, armed to the teeth with a computer, a
modem and an extra serial port is far better equipped &
prepared for a massive frontal assault on the airwaves
than entire legions of radio experts of only a few years
ago! There are many reasons for this, including rapidly
advancing technology, but ACCESS to INFORMATION is one
and is the focus of this special article.
You see, information exists everywhere, but getting to it
or accessing it can be a different story. Even public
libraries, traditional storehouses of information, are
rarely convenient and accessible at the precise moment
you need a bit of data, On the other hand, a virtual
treasure trove of information can be no farther away than
your computer and only seconds away from your eyes and
mind. Consider that it might take several minutes or
longer to research a certain scanner frequency in Police
Call & other directories but only a few seconds from the
memory banks of your computer. Ok, you might ask, a
computer is really dumb unless it is programmed with data
so how do I get that data in the first place? A fair
question. There are a number of ways to put information
into your computer and there's no escaping the fact that
the task can resemble that of assembling and maintaining
a home library of books and files. I said "resemble".
Actually, it’s a lot different in action, requiring much
less energy, time, space and cost. One of the most
effortless and least costly resources of information for
your computer files can be found in a public network of
computer bulletin board systems called the FidoNet.
'Twas in 1984 when a few computer nerds, including Tom
Jennings, started a small message network. Word of this
spread like wildfire. Their system evolved into a world
wide network of 8,000 nodes by 1990. Today this fabulous
network has over 14,000 participating BBS's with dozens
in every metropolitan area.
The FidoNet vaguely resembles Citizens Band and Amateur
radio in the sense that it is a medium through which
thousands of people communicate with others of like
interests across town, state, country, geographical and
political borders and even oceans, all from the comfort
of the home or office. If you have a telephone line, a
computer, a modem and software to run the modem, then the
cost to tap into this leviathan storehouse of information
can be virtually nothing, and certainly very low. Chances
are that one or more Fido BBS's are located in your local
telephone calling area. You only need call and log on to
any Fido BBS to be connected into this worldwide network.
If that BBS is located within your local calling area,
there is usually no cost. You see, the FidoNet consists
of more than 14,000 amateur BBS's around the world with
over 10,000 in the USA and Canada alone. It is expressly
forbidden to use the FidoNet for commercial purposes.
Therefore, if you can find a Fido BBS in your local
calling area, chances are you won't have to spend a dime
to link up with the world! The SysOps are private
people, and just like us, are very dedicated to their
hobby. They pay for their computer equipment and phone
costs just like we do. A rare few BBS's may levy a
monthly membership fee, but these guys are either very
stupid or else they have a system so well setup that a
fee is worth it. In any case, most BBS's are FREE access
and therefore you can freely connect with the world!
Think of FidoNet as a CB radio with over 500 channels or
"Echoes", each of which is dedicated to or focused on a
special interest topic. One Echo in particular and in
which you will be keenly interested is the "Shortwave
Echo", which is dedicated exclusively to Shortwave
Listening and VHF-UHF Scanning. Other "Echoes" are
dedicated to Ham Radio, Broadcast radio, satellite TV,
knitting, coffee-lovers, law, medicine, arts, crafts,
etc. There are Echoes for religion, politics, adult
subjects, recreation, travel, computers and of course,
hundreds more. The one in which we are interested is the
No single Fido BBS carries all 500+ Echoes, so you might
have to search out a few BBS's before you find one that
has the Shortwave Echo. You might not find any local
BBS's that carry it, but don't despair; you have options:
(1) call other Fido BBS's in nearby toll areas. If you
call at night, tolls can be rather low and painless to
your budget, or (2) Contact the System Operator (SysOp)
of each BBS in your calling area and ask if he/she will
carry the Shortwave Echo for you or help you find a BBS
that does! A primary objective of a Fido-BBS is to carry
Echoes that will draw and appeal to their patrons. The
SysOps KNOW it's wise to cater to the needs of their
patrons, so they will usually have an open mind to your
request. As you contact first one BBS and then another,
ask the SysOp if any BBS's in your local area carry the
Shortwave Echo. SysOps have a comrade spirit, so they
pretty much know each other and which Echoes are carried
by the various BBS's. You'll find one in a short time,
if you don't luck out on the first few tries. Now, here
is one scenario of how the FidoNet Shortwave Echo works:
I log into my local Fido "node" (BBS) every morning to
read all the new shortwave & scanner messages that have
come in since the day before. When there is a message of
interest to me or which needs my response, I'll usually
compose a reply on the spot. Throughout the day, my BBS
dumps the day's traffic back upstream to a "Hub", which
in turn dumps the traffic from a number of nodes further
upstream to a "Host'' which then dumps a greater volume ot
traffic into a "Gateway". The Gateways then circulate
all that traffic around to the various "Hosts" and "Hubs"
and in turn, back down to the "nodes". So if I send out
a message today, it will circulate throughout the system
during the day and that night so that everyone who
participates in the Shortwave/Scanner Echo will see my
message the following day. If a reply is made at that
time, I'll probably receive it the following day.
If it sounds complicated, relax, because you don't really
care what happens or how it happens. All you have to do
is read the daily messages which interest you and respond
if and when you want. It will come to you, after a few
sessions, how easy it can be to affiliate with thousands
of other radio hobbyists. You will find people from all
walks of Life participating on the FidoNet Shortwave/
Scanner Echo, including experts, dealers and Who's Who
kinds of people right down to the greenest neophytes.
Again, relax, because it's an informal setting where the
greenest neophyte and the most grizzled expert are on
equal footing. Participation on the Shortwave/Scanner
Echo is a great way to pick up the inside scoop on
everything in radio from what's hot and what's not to
hints, tips, tricks, and answers to your most profound
questions about everything from Antennas to Impedance.
In addition to the public message system, FidoNet also
has a semi-private NetMail system for SysOps to send
E-Mail between themselves, off the side and away from the
Public Message areas. Many SysOps allow their users
NetMail privileges, too. Fido’s NetMail system is a lot
like E-mail in other information services; a handy, quick
and pleasurable way to communicate with others on a
reasonably private basis. Some SysOps restrict NetMail
privileges so it may not be available, depending.
Least well known, but very potent is FidoNet's informal
"library system" called FREQ or "File REQuests". Most
BBS's maintain large data file storage areas filled with
everything from freeware and shareware computer programs
to volumes of information on various subjects. Since
radio is a hobby and a pursuit of specialized interest,
most BBS's won't stock radio related information in their
File Sections unless the SysOp is a radio buff like us...
BUT....there are a number of radio-exclusive specialty
BBS's around the world which stock hundreds of megabytes
worth of radio information on every subject you can think
of, again from antennas to impedance, including product
reviews, mods, and resource lists. Most Fido BBS's can
File Request (FREQ) so it may be possible for you to get
the SysOp to obtain certain data files for you if you
know what to ask for and where they can be found. You
can also get files direct, once you know how. Think of
this file system as a huge "library" system which can be
operated right from your Keyboard. This is getting a
little advanced for an introductory article, but I wanted
to give you an overview of what the FidoNet is all about.
First, you have to get connected. Most any computer with
a 1200 baud or faster modem will do, though turtle's pace
"THE WORLD SCANNER REPORT" (c) 1991-2; V2N4 - April, 1992; Page 2
300-baud modems can work fine with many systems. Next,
you have to find a FidoNet BBS. There are several ways
to do this. If you already do modem/BBS work, then you
have a head start. Just ask the SysOps of your favorite
BBS's where you can find a Fido BBS. You might already
be affiliated with one and not be aware of it! If you are
new to modeming, then one sure bet is to call a computer
store and ask if they have a list of local BBS's in your
area. Most will and you’ll be on the way. Again, just
log on to a few BBS's and ask the SysOps about FidoNet.
You will find one quicker than you think, because SysOps
are thicker than fleas and they know who's who and who
specializes in what. When you find a Fido BBS and you
surely will, then determine if it carries the SHORTWAVE
echo and if not, ask or beg for it.
If worse comes to worse and you just can't find a Fido
BBS in your area, send me a SASE and TWO loose extra
postage stamps along with a mention of your telephone
Area Code. I will prepare for you a list of Fido BBS's
in your Area, arranged in telephone number order so you
can easily determine which are local. It is a good bet
that you’ll have 10 to 100 or more from which to choose!
For example, the Michigan (313) Area Code has 135 Fido
BBS's; my (619) area code has a hundred.
This introduction has only scratched the surface of the
FidoNet and how it can be used to enhance your radioing
pleasure. I could not possibly explain it to the detail
that I would like, even if I used all eight pages of this
issue. You're just going to have to try it for yourself.
You'll see. And if you have any trouble, let me know and
I'll see what I can do to smooth the way for you. In
summary, let me just say that the FidoNet and a computer
can bring a worldwide radio club right onto your desk
along with a library of info and data. Every morning I
rise to a steaming cup of fresh ground Colombian Supremo
coffee and a roundtable discussion with radio enthusiasts
around the world from Germany, Netherlands, England,
Australia, Canada and virtually all 50-states of the USA.
Even as I awaken, a wealth of info and data lies at my
fingertips. All this_and much more can be at YOUR
fingertips, too! If this doesn't motivate you to join
the Fido Radio Gang, write to me and tell me what will!
Now, continuing with 1992's focus on computers to enhance
the enjoyment & rewards of radio, Perry Joseph joins us
to build upon the foundations he laid down last month:
SCANNER FREQUENCY MANAGEMENT - Part 11
by Perry Joseph, President, DataFile, Inc.
Last month, I discussed several "manual" solutions for
keeping track of scanner frequencies and their licensees.
In this article, I will discuss the use of computers as a
more efficient means of maintaining frequency lists.
My first experience with microcomputers dates back to
1983 when I worked as a salesman for industrial video
gear at a local video store. The owner decided to carry
Apple Computers. The first Apple was a humble product.
Loading data and software into the computer required a
modified cassette deck. It took several minutes just to
get the darn thing to produce it's first screen of info.
But it was a cheap, new toy for the consumer market. I
never took the Apple Computer too seriously. It was
great for playing games. Let’s face it, anything beat
"Pong” in those days. The Apple's primary drawback was
speed: a lack of it. It wasn't until we purchased an IBM
"XT" microcomputer that I started to actually use one for
anything other than entertainment. Even then, it was only
equipped with floppy disk drives.
A year or so later, we purchased an IBM "XT" with a hard
disk system so large amounts of data could be maintained
at a reasonable cost. The microcomputer had found its
place in the small business environment. In the latter
part of 1986, I decided that microcomputers were the next
great product of the electronics industry. I resigned my
job, purchased a computer system and started DataFile.
Any basic "Computer 101" course or book, categorizes
software into five basic groups: word processing, record
keeping (database management), communications (using a
modem, etc.), spreadsheets (accounting, math, etc.) and
graphics (computer aided drawing, games, etc.). The
first two categories, word processing and record keeping,
can be applied to manage our scanner frequency lists.
My first experience with computerizing frequency lists
was to enter the data into a word processor. A Word
Processors is a quantum leap for anyone who has ever used
a typewriter to make letters & lists. Word processors
allow you to enter, manipulate, format, print, store and
retrieve text. Other features might include word wrap,
scrolling, insertion, deletion, move, search and undo.
Naturally, I created lists of names and frequencies in
the word processor. Now I could change a name or a freq
and reprint an updated list without the scribble of
"handwritten days past". Changing a name or a freq was
easy since my WP had a "search and replace" feature.
A word processor had definite advantages over handwritten
notes, but lacks a few needed functions. Real control
and "manipulation" of frequency data requires a "record
keeping system", better known as a "database" program.
Database programs allow you to search, add, delete, sort,
update, print and do some math calculations. What's that?
Word processors do the same thing? There is some truth
to that with exception that databases tend to do more and
do it better when it comes to pure record keeping.
Database managers offer standard groups of features which
can be selected through choices displayed in the menus.
Enhanced features may include creating custom screen
displays, custom reports and displaying "help" screens
with menu choices and explanations to guide the new user.
Database programs generally treat information as some
form of a "record". As an example, a frequency record
"THE WORLD SCANNER REPORT" (c) 1991-2; V2N4 - April, 1992; Page 3
might hold the following information, typically organized
in columns or descriptions called "Fields" or Categories.
A database program affords the power to sort or "index"
groups of records alphabetically, numerically and some¬
times even chronologically (date/time order). Sorting or
indexing allows us to look at or retrieve records in a
number of ways. Records can be sorted by one or more
field names, typically called "key field(s)".
For example, if we sort our records by licensee name
first and frequency second, and if there are a number of
records with the same licensee name, the sorted list will
group these names together in name order followed by
their related frequencies in numerical order. Using this
same sorted list, we can print our records on a select or
"filtered" basis. For example, we could print a report
for all licensee names that begin with "A", or all
licensees on frequencies between 460-4713 MHz.
The winning edge of using a database manager over a word
processor in organizing my frequency list was speed and
the ability to manipulate my information. A data base
let me look up and change records with little effort. I
could easily compare my list with another list without
concern for the order of the "other list". Checking for
duplicate frequencies was a snap. I went on to customize
my screens so that a record consisted of the specified
data. I created enumerable customized reports to enhance
my enjoyment of scanning.
A growing body of scientific evidence now points toward
the possibility of predicting major seismic events based
on low frequency transients. Probably the most widely
known investigation was conducted by a team headed by
Anthony Fraser-Smith of Stanford's Star Lab. This study
found distinctive patterns in the 0.05 to 10 Hertz range
(yes, Hertz, not kHz.). The Fraser-Smith study was based
on experiments conducted in the Soviet Union, which in
turn grew out of folklore from China and Japan. Joe Tate
and William Daily found anomalies in the 1-10 kHz range,
while others report signals to 100 kHz. Among amateur
radio operators there are many anecdotal incidents of
earthquake transients all the way up to the HF range.
My idea is to create a network of amateur monitors for
the following ranges:
1. The 0.01 to 12 Hertz range. Joe Tate, and Anthony
Fraser-Smith have done successful experiments in this
range, but they are extremely difficult and
expensive. The Schumann resonances come into play,
man-made interference is a problem and specialized
digital equipment may be necessary.
2. The audio portion of the electromagnetic spectrum,
200 Hz to 15 kHz. Conversion Research, PO Box 535,
Descanso, CA, has an excellent broad range, untuned
receiver on the market for only $48, and this may
work well for our purposes.
3. A tuned receiver for about 8 to 50 kHz, with about a
2 to 3 kHz bandpass. This is the range that several
experimenters, including Jack Coles of Santa Clara,
California, claim is effective. There have also been
some Japanese experiments in this range.
Next month I will tell you about some of the more popular
database programs, some considerations that go along with
purchasing one and the type of database software used to
create ProScan™, a Frequency Management System.
4. A tuned receiver for 30 to 150 kHz, with adjustable Q
for selectivity or broad coverage, again of 2 to 3
kHz bandpass. A simple converter may be applicable
here. Again several experimenters have found
possible quake precursors in this range.
A SCIENTIST CALLS OUT FOR HELP FROM RADIO HOBBYISTS!
I am conducting research into experiments that record low
frequency electromagnetic disturbances associated with
earthquakes. I would ask you to post the attached article
or, if you have a newsletter, to include it, provided you
feel the subject matter is appropriate for your members.
I am looking for anyone who has been or wants to be
involved in amateur research in this field. Thanks in
advance for your help. Rspy, Vince T. Migliore, Editor
EARTHQUAKES AND ULF MONITORING
Earthquakes are sometimes preceded by/linked with curious
electromagnetic signals in the lowest frequency ranges.
These signals can be detected by equipment in many radio
shacks. I am trying to collect data on and stimulate
amateur experiments aimed at monitoring ultra-low freq
(ULF) phenomena that may be associated with earthquakes.
Of course we'll have to include coverage of antennas,
amplifiers, tuning circuits and interfaces to computers
or strip chart recorders.
I think the best approach is to focus on one design in
each category. I have at least some skills in writing
and research, but I need help with circuit design and
engineering. I know, too, that some amateur radio
operators and engineers are already tinkering with these
ideas. My request therefore is to hear from anyone who
has been or wants to be involved with low frequency
monitoring for earthquake precursors.
I am presently editor of a newsletter dedicated to
earthquake prediction, amateur geo-physical monitoring
and earth mysteries. For a free sample issue and a ULF
bibliography, please send a large SASE ($0.75) to me:
Geo- Monit or MM, 65 Washington St, S ant a Cla ra, CA 9 5050
"THE WORLD SCANNER REPORT" (c) 1991-2; V2N4 - April, 1992; Page 4
Geophysicists are at a loss to explain any mechanism that
might account for seismic electromagnetic and magnetic
disturbances but some theories include the piezo-electric
effect of crushing & bending of quartz-containing rock in
the earth's crust; the flow of magma beneath the crust
that may contain metals, and the interaction of the
earth's magnetic field with the solar wind. None of
these models however is fully satisfactory. By organizing
a good sized network of amateur monitors, we may be able
to shed some light on this exciting new science.
1. Radio Earth: The Radio-Seismic Connection. Joe
Tate, Whole Earth Review, Fall, 1990.
2. Sferics: a Beginner's Guide to Whistlers, Tweeks and
Other Natural Radio Sounds and how to hear them.
Mike Mideke, Whole Earth Review, Fall, 1990.
3. Build the 'Whistler' VLF Receiver. Tom Fox, Popular
Electronics, July, 1989.
4. Amateur VLF Observations. W.C. Johnson, QST
magazine, March, 1960.
5. ULF, ELF and VLF Electromagnetic Field Observations
Close to the Epicenter of the 7.1 Loma Prieta
Earthquake: Possible ULF Precursors.
A.C.Fraser-Smith, A. Bernardi, P.R. McGill, M.E.
Ladd, R.A. Heliwell, and O.G. Villard, Jr., STAR
Laboratory, Stanford University.
I have completed an intermediate technical evaluation of
the I COM R-1, DC-to-Daylight pocket scanner; an awesome
little package of dynamite! My investigative focus was
on the alleged and much-talked-about deficiencies of this
unit; not on its numerous strengths & good points, which
are well documented elsewhere. The result of my analysis
is that I will not be adding the R-1 to my arsenal of
monitoring equipment at any time in the near future; not
because of any new discoveries or the deficiencies that I
found, but because the danged thing is so tiny and micro¬
miniaturized that it is next to impossible to do anything
with it, either to cure its few shortcomings or to add
anything new and exciting.
The R-1 has three serious problems: susceptibility to (1)
strong signal overload, (2) adjacent channel interference
mostly on AM in the LF-MF-HF bands where selectivity is
vital and (3) spurious interference caused by internal
mixer and/or intermod products. Poor selectivity in this
unit results from the barn-door-wide 455 KHz IF filter on
the DET-A board, which is used in common with both the AM
and NFM modes. The 15 KHz width of this filter is more or
less satisfactory for VHF/UHF NFM requirements but much
too wide for LF-MF-HF AM shortwave bands where signal
separation can be as little as 3 KHz. Imagine then, up to
five different signals on one channel. No thank you!
The exact source of the spurious interference is elusive
but might be caused by dirty local oscillators (VCO) and/
or an inferior "clean-up" filter, FI-1, in the main unit.
It seems that a company in England, RAYCOM, is doing a
mod that eliminates most of the objectionable spurious
interference on the VHF/UHF bands. I suspect RayCom's
technique involves replacement of FI-1, a 10.7 MHz 2nd IF
crystal filter with perhaps a better unit. It's possible
that the stock ICOM filter is defective or out of spec if
RayCom's modification actual It replaces FI-1.
So what about a remedy for inferior Adjacent Channel
Rejection? I think it is possible to replace the 455 KHz
IF filter on the DET-A board with a narrower much sharper
IF filter. I won't attempt that approach at this time
for several reasons. The problem as I see it, is two¬
fold: first there is the matter of space or available
real estate in the R-1; zilch. All decent IF filters of
which I am aware are somewhat larger than the stock FL-1,
and therefore will not find an easy residence. But even
if one is found, a serious problem will remain!
A useful IF filter for LF-MF-HF AM operation, say with a
6 KHz bandwidth, will be too narrow for most NFM signals,
especially at VHF & UHF. A 6 KHz IF filter will clip FM
signals that are deviated more than 3 KHz, as is usually
the case. Therefore, an ideal remedy for poor Adjacent
Channel Rejection is the installation of a narrow IF
filter that is auto-switched INTO the circuit whenever
the AM mode is selected and OUT for NFM. An ideal
approach that won't cause more problems than it resolves
is not yet at hand because of space limitations and
probable unavailability of a miniature IF filter. Fig-1
depicts what I think is a correct approach, but schematic
diagrams don't always convey the mechanics of things.
I am uncomfortable at performing mods that can't be made
fairly professional as if they were designed there in the
first place. Therefore, I will not perform modification
services to the R-1 in the near future, and at least not
until more information and experience on the unit become
available to me. At this time, I view any easy remedy
for the poor selectivity as a probable cause of other
problems where there were none before; limits to the
utility & usefulness of the VHF-hi & UHF bands where a
full bandwidth of the NFM IF filter is usually required.
There is the matter of strong signal overload which
pretty much eliminates the use of external antennas and
preamplifiers for the R-1. It is not feasible to remedy
this deficiency. An exemplary reason for the overload
problem is that the RF Front End of the R-1 does not
employ AGC (Automatic Gain Control), therefore it can
operate only over a limited range of amplification before
it is driven into cutoff and saturation, either/both of
which produce symptoms of overload including clipping,
distortion, desensitization, spurious & pseudo signals
across the band. The only practical remedy for this
deficiency is to reduce the signal strength into the R-1,
either by a less efficient antenna or by an attenuator
between the antenna and the receiver. Neither is what I
’"THE WORLD SCANNER REPORT" (c) 1991-2; V2N4 - April, 1992; Page 5
call very appropriate for a serious receiver. Nice job,
there I COM, but no banana for you yet!
One possible remedial approach to the AM selectivity
problem of the R-1 (for you adventuresome hackers), will
be to intercept a signal trace in series with FL-1 on the
DET-A board, either into or out of the filter. A suitable
point on this circuit trace will be broken and a narrow,
sharper 455-KHz IF filter wired between the trace cut so
as to be in series with FL-1. To make the new filter
auto-switch in and out, depending on AM or NFM mode, the
IN & OUT terminals of the new filter should also connect
to the IN & OUT terminals of a CMOS bilateral switch such
as a 74HC4066 with the control pin of the 4066 connected
to the Q-7's Collector either Base of Q-5 on the DET-A
board. This is a +5v control signal for the NFM/WFM
modes (0-v for AM) which will enable the 4066 switch to
bypass the new filter in the NFM/WFM modes, and to be
active in the AM mode. Some refinement to this approach
may be necessary for ultimate best results, but it sure
seems the way to go at the moment for the researcher.
For those who can't visualize this technique, Figure 1
offers a schematic diagram of the DET-A board and the
method. Theoretically speaking, here is what happens:
An SPST switch is connected to the IN & OUT terminals of
the new filter. When the switch is closed, the filter is
effectively shorted out, thereby routing signals around
the new filter. When the switch is open, signals have to
pass through the filter. The Collector of Q-7 or either
Base of Q-5 on the DET-A board offers this Mode Control
Signal, which can be used to control a 74HC4066 bilateral
switch to bypass the new filter as desired; i.e., OUT for
AM, and IN (shunted) for NFM & WFM.
NOTE: A 74HC4066 chip is rather large for the R-1, so a
suitable alternative might be a TC4S66F (IC-10 in the
PRO-2006) or a replacement TC4S66F (IC-2 on DET-A of the
R-1). The TC4S66F is a very small single section SMT
CMOS bilateral switch.
In summary, the front-end overload problem cannot be
remedied. AM selectivity can be greatly improved by
simple replacement of the 455 KHz IF Filter but this will
degrade the performance of the NFM mode in the VHF-UHF
bands. Depending on your interest, the tradeoff of one
serious problem for another is not a good way to go. The
technique offered in Fig-1 will improve AM selectivity
but not at the expense of degrading NFM/WFM performance.
The jury is still out on spurious interference problems
and more research and analysis is required before we
settle on a solution. I keep hearing that RayCom of
England has solved this problem, but they're not sharing
the "secret" with anyone, so I would like to hear from
you who had this procedure done. I would like to test
and observe an R-1 that was modified by RayCom. At this
point, my concern is that in solving one problem, they
may have created other, possibly worse ones. Figure 1
offer a clue for eliminating the spurious interference.
Finally, we have to look with a jaundiced eye at the
feasibility of invading and hacking the R-1. After
careful review of the innards of the R-1, I can only
conclude that due to its compressed design and lack of
working room, there is a substantial chance of serious
error, mechanical and/or electrical, associated with an
invasive effort. This makes a commercial hacking venture
quite unfeasible and at best, very risky to the hacker.
Not many pro's can afford to replace a mis-hacked R-1 at
current prices, you see. Neither can hobbyists, so any
amateurish invasion with the idea of correcting the R-1's
selectivity problems is ill-advised at this time. I do
not say that it's impossible since further research and
development may yet disclose a viable approach. Any such
are not apparent right now.
RUMORS OF A NEW PRO~2006(Aj
A source that I will call "reliable" because he claims to
be an eyewitness, recently confided to me that he saw a
PRO-2006 that somehow didn't "look right”. Sure enough,
instead of a DIMMER SWITCH, it had a switch in the same
place, but marked "LIGHT". According to the source,
pressing that switch caused the blue background display
lighting to turn on and off! He also noted the Radio
Shack catalog number on the rear label to be 20-145A,
which certainly would imply a recent production change
somewhere along the line. My source is not a technical
type so he was not able to assess his observation unit
for any possible internal changes or upgrades. If YOU
READERS see or hear of this variant PRO-2006A, please let
me know what you learn, otherwise.read on.
RUMORED THAT THE PRO-2006 IS BEING DISCONTINUED
A Radio Shack store manager confides that the PRO-2006
might be discontinued. He reports receiving a notice
from a distribution center to get his order placed soon
for all needed PRO-2006 stocks because they were being
discontinued. Ordinarily, I would not print this info
here, but an exception is made because I know how Radio
Shack's system works. You see, the PRO-2005 was replaced
in exactly the same manner in the same time period of the
year_May, 1990. I worked part time for a Radio Shack
store then and saw how the process worked. Lots of new
merchandise for the coming year's catalog that begins in
August of each year starts to appear, unannounced, on the
shelves in the Apri1-May period. If a replacement for the
PRO-2006 is on the way, then expect a sale on existing
stocks and watch for the replacement to hit the shelves
between May & August. I do not have a feel for what the
replacement, if any, will be like. Given the current
drive in Congress to outlaw the manufacture & importing
of cellular-capable receivers, it is possible that any
replacement will have cellular coverage permanently
locked out! It might very well be that the PRO-2006A
discussed above was an early advance model of the
replacement. I just don't know any more to tell you at
the moment, BUT..if you were planning to acquire one,
- = Continued on Page 8 = -
"THE WORLD SCANNER REPORT" (c) 1991-2; V2N4 - April, 1992; Page 6
CONFIDENTIAL SUBSCRIPTION ORDER: Please print clearlv I V2N4
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VHF-UHF Amateur CB Shortwave Professional
List makes & models of your scanners & other radio equipment:
13/27/92 SUBSCRIPTION RATES i ORDER BLANK V2N4
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NSR BACK ISSUES ONLY USA IS Check Items
1991 Single copies; your choice: I ea $ 4.00 _
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NSR CURRENT SUBSCRIPTIONS ONLY
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OTHER LITERATURE AVAILABLE
H088Y RADIO BUYER'S DIRECTORY $14.95 ppd surf _
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use OUK A/£ZISS ftiR QUICK /ZesfbA/^g'
this may be the time, especially if they go on sale.
Watch for one soon! Meanwhile, if you want to take
advantage of a regular low price on the PRO-2006 and even
lower prices when a sale is authorized, contact MaryMac
Industries in Katy, Texas (800) 231-3680 and ask for
Bruce. Tell ’im I sent ya. MaryMac's regular price on
the PRO-2006 is about $340, but if Tandy authorizes a
closeout sale, their price will be lots lower still!
When Radio Shack last had the PRO-2006 on sale for $349,
MaryMac's sale price was $299. Nice, huh? Wish I could
advise you on the correct decision to make here, but I
don't dare. The 2006’s replacement, if anything, could
be a downgraded 2006 with a few cheap frills to make up
for the loss of cellular coverage, OR it could be the
best, hottest scanner yet. My sneakiest suspicion is
that cellular coverage might not be possible to restore
in coming generations of scanners. So, the decision is
up to you: if the budget is tight or if you really don’t
care about near-continuous coverage, then you might be
better off to wait for the new generation. If near-
continuous coverage is important and if your budget isn't
strained, then you might want to take a long look at the
PRO-2006 before its death knell sounds.
The PRO-2006 is sure to not become outdated and behind
the times very soon, especially considering the upgrade
modification technology that I have developed & conveyed
for this fine scanner. Regardless of the replacement,
and there will surely be one this year or next, the
venerable 2006 will remain a top-of-the-line performer
for several years. About the only additional power that
Radio Shack can provide in a replacement in an attempt to
antiquate the 2006 would be an interface & software for
computer control. Rumors of such a powerhouse have raged
around the professional grapevine for almost a year now,
but I've minimized talk about it because it sounds more
like wishful thinking than reality. Besides, Radio Shack
was beaten to the punch in VINI0 & V2N1 with the do-it-
yourself FATMAN Computer Interface; RW Systems added
"THE WORLD SCANNER REPORT" (c)
insult to injury with their SC-3 Interface Kit; and
Oatametrics pulled a coup d'etat witn their Computer
Aided Scanning System. Sometimes I feel like that stupid
Commissioner of Patents a hundred years ago, who resigned
his office on the basis that there was nothing else to
invent. Well_what else can Radio Shack whip out to
impress us with? An S-meter? A variable delay? A few
thousand channels? Data/Tone Squelch? CTCSS & other
Tone Decoders? Yup, you've got all those and much more!
So your PRO-2006's, AND....PRO-2004's & PRO-2005's are
going to be competitive performers for a long time yet.
Now let's see what surprises are in store.
MORE O N CTCSS & CTCSS TONE DECODERS/TONE FINDE RS
We're going to deal with CTCSS (Continuous Tone Coded
Squelch Systems) and associated peripheral equipment in
the near future. I'm fond of whetting your appetites,
though, and in closing for this month, I wanted to clue
you in on a neat little company in South Carolina called
AUTOMATED INDUSTRIAL ELECTRONICS CORP. AIE has been
around for a while, but I’ve come to learn of them only
recently as my research into the CTCSS industry widened.
AIE makes some pretty neat CTCSS-related stuff for
scanners and you would do well to prepare yourselves with
their product literature for the coming months when we
will evaluate and discuss their fare, from Tone Finders
to computer-interfaced Tone Search & Store units. Write
or call AIE at: 141 Granite St/PO Box 70; Batesburg, SC
(803) 532-9256 & Fax (803) 532-9258.
FOR SALE: Brand new, unopened AIE Model TCF-3M CTCSS
Tone and Digital Code Finder; instantly finds & displays
all CTCSS & digital codes, incl split channel & inverted
codes. Memory retains all hit & time info which can be
transferred to a printer via on-board RS-232 port. More!
Retail @ $339.95, this unit oniy for $300 ppd ; w/manual.
For Uniden BC-760/950XLT & Regency R-1600 only. Inquire
to Bill Cheek c/o "NORLD SCANNER REPORT".
1991-2; V2N4 - April, 1992; Page 8
"THE WORLD SCANNER REPORT"
PO BOX 262478
SAN DIEGO, CA 92196-2478
IN THIS ISSUE FIRST CLASS NAIL
t TIME TO RENEW APPROACHING: Next issue the last for May-92 Subscriptions
t Try different hours for the Hertzian Intercept BBS: (619) 578-9241
t INTRODUCING: The worldwide FidoNet BBS Network; Hobby Radio's finest tool!
+ Scanner Frequency Management, Part II; gets deeper!
t A scientist calls out for HELP from radio hobbyists
+ Radio signals as warning signs of impending earthquakes ? Maybe!
+ The latest technical evaluation of the ICON R-1: problems 4 deficiencies
t ICOM R-1 problem resolution guide 4 notes
t Rumors of a new PRO-2006(A) ? the evidence
t Rumored that the PRO-2006 will be discontinued soon!